libstdc++-v3/include/ext/string_conversions.h

   1 // String Conversions -*- C++ -*-
   2
   3 // Copyright (C) 2008 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #ifndef _STRING_CONVERSIONS_H
  31 #define _STRING_CONVERSIONS_H 1
  32
  33 #pragma GCC system_header
  34
  35 #include <ext/numeric_traits.h>
  36 #include <bits/functexcept.h>
  37 #include <cstddef>
  38 #include <cstdlib>
  39 #include <cwchar>
  40 #include <cstdio>
  41 #include <cerrno>
  42
  43 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
  44
  45   // Helper for all the sto* functions.
  46   template<typename _TRet, typename _Ret = _TRet, typename _CharT,
  47            typename... _Base>
  48     _Ret
  49     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
  50            const char* __name, const _CharT* __str, std::size_t* __idx,
  51            _Base... __base)
  52     {
  53       _Ret __ret;
  54
  55       _CharT* __endptr;
  56       errno = 0;
  57       const _TRet __tmp = __convf(__str, &__endptr, __base...);
  58
  59       if (__endptr == __str)
  60         std::__throw_invalid_argument(__name);
  61       else if (errno == ERANGE
  62                || (std::__are_same<_Ret, int>::__value
  63                    && (__tmp < __numeric_traits<int>::__min
  64                        || __tmp > __numeric_traits<int>::__max)))
  65         std::__throw_out_of_range(__name);
  66       else
  67         __ret = __tmp;
  68
  69       if (__idx)
  70         *__idx = __endptr - __str;
  71
  72       return __ret;
  73     }
  74
  75   // Helper for the to_string / to_wstring functions.
  76   template<typename _String, typename _CharT = typename _String::value_type>
  77     _String
  78     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
  79                                  __builtin_va_list), std::size_t __n,
  80                  const _CharT* __fmt, ...)
  81     {
  82       // XXX Eventually the result will be constructed in place in
  83       // the C++0x string, likely with the help of internal hooks.
  84       _CharT* __s = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT)
  85                                                           * __n));
  86
  87       __builtin_va_list __args;
  88       __builtin_va_start(__args, __fmt);
  89
  90       const int __len = __convf(__s, __n, __fmt, __args);
  91
  92       __builtin_va_end(__args);
  93
  94       return _String(__s, __s + __len);
  95     }
  96
  97 _GLIBCXX_END_NAMESPACE
  98
  99 #endif // _STRING_CONVERSIONS_H